Subframe assembly for a vehicle

ABSTRACT

A subframe assembly adapted to receive and secure an engine or motor in a vehicle, the subframe assembly including: a crossmember; an arm member coupled to each end of the crossmember; and a corner member coupled to each arm member adjacent to a corresponding intersection with the crossmember, wherein each corner member includes an upwardly protruding shelf structure defining a plurality of threaded holes adapted to receive a plurality of attachment bolts for securing a corresponding engine mount or motor mount to the subframe assembly. Each corner member includes a horizontal arm disposed along an upper surface of the corresponding arm member and a vertical arm disposed along an outboard surface of the corresponding arm member, wherein the horizontal arm includes the upwardly protruding shelf structure.

TECHNICAL FIELD

The present disclosure relates generally to the automotive field, andespecially the electric vehicle (EV) field. More particularly, thepresent disclosure relates to a subframe assembly (e.g., a frontsubframe assembly) for a vehicle that includes integrated shelfstructures in corner extrusions (e.g., front corner extrusions) thereof,enabling engine mounts or motor mounts to be bolted to the subframeassembly from above during production while maintaining structuralstrength and overall vehicle integrity.

BACKGROUND

In some conventional internal combustion engine (ICE) vehicle and EVdesigns, the engine or motor is coupled to a front (or rear) subframeassembly that may be extruded for weight and costs savings, as well asstructural strength and overall vehicle integrity in the event of acrash. Extruded aluminum provides many advantages over conventionalsteel box and/or cast constructions. This subframe assembly typicallyconsists of a frame-like structure that includes at least one extrudedcrossmember (and likely a pair of extruded crossmembers) disposedbetween a pair of elongate extruded arm members. The engine or motor issecured to the subframe assembly via engine mounts or motor mounts thatare secured in the corners of the subframe assembly. In the case of afront subframe assembly, the front engine mounts or motor mounts aresecured to front corner members that are welded or otherwise affixed tothe arm members near their intersections with the front crossmember,and/or to the arm members and front crossmember themselves. A similararrangement can be used for the rear engine mounts or motor mounts, orwith a rear subframe assembly.

Typically, the engine mounts or motor mounts are secured to the armmembers and crossmember of the subframe assembly via bolts that pass atleast partially through the arm members and crossmember, throughoversized/threaded sleeves that protrude from the bottom surfaces of thearm members and crossmembers, and are secured from below. Thisintroduces manufacturing complexity, tolerance and angle-mismatchproblems, and is undesirable from an ergonomic standpoint. Longer boltsand sleeves further add material to the process. Alternatively, theengine mounts or motor mounts are secured to the corner members and armmembers and crossmember of the subframe assembly via bolts that pass atleast partially through the corner members and arm members andcrossmember, through oversized/threaded sleeves that protrude from thetop surfaces of the corner members and arm members and crossmembers, andare secured from above. Again, this introduces manufacturing complexityand tolerance and angle-mismatch problems. Sleeves further add materialto the process.

The above-described background relating to engine mounts and motormounts is merely intended to provide a contextual overview of somecurrent issues and is not intended to be exhaustive. Other contextualinformation may become apparent to those of ordinary skill in the artupon review of the following description of exemplary embodiments.

SUMMARY

The present disclosure generally provides an assembly and method thatallows the engine mounts or motor mounts of a vehicle to be assembledfrom above, providing ergonomic advantages, while eliminating the use oflonger bolts and threaded sleeves to the extent possible. The use ofextruded (aluminum) structures is provided herein to provide the desiredductility and crashworthiness.

In general, the present disclosure thus provides a subframe assemblythat is adapted to receive and secure an engine or motor (i.e., apropulsion device) in a vehicle. The subframe assembly generallyincludes an extruded aluminum crossmember and an extruded aluminum armmember coupled to each end of the crossmember. An extruded aluminumcorner member is coupled to each arm member adjacent to a correspondingintersection with the crossmember. Each corner member includes anupwardly protruding shelf structure itself defining a plurality ofthreaded holes adapted to receive a plurality of attachment bolts forsecuring the corresponding mount (e.g., engine mount or motor mount) tothe subframe assembly. This shelf structure is a solid structure that isextruded with the remainder of the corner member, providing anintegrated structure that avoids the brittleness problems associatedwith cast components and the failure problems associated with weldedcomponents. Each corner member includes a horizontal arm disposed alongan upper surface of the corresponding arm member and a vertical armdisposed along an outboard surface of the corresponding arm member. Thehorizontal arm comprises the upwardly protruding shelf structuredefining the plurality of threaded holes adapted to receive theplurality of attachment bolts for securing the corresponding enginemount or motor mount to the subframe assembly. The crossmember definesone or more additional threaded holes at each end adapted to receive acorresponding one or more additional attachment bolts for securing thecorresponding engine mount or motor mount to the subframe assembly.Additional crossmembers may be utilized and, again, each of thecrossmembers, arm members, and corner members may be extrudedstructures, with the uninterrupted length of the arm members beingmaximized. It should be noted that a front subframe assembly and frontengine mounts or motor mounts are the general focus of the presentdisclosure, however the principles thereof apply equally to rear enginemounts or motor mounts and/or a rear subframe assembly, when applicable.

In one exemplary embodiment, the present disclosure provides a subframeassembly adapted to receive and secure an engine or a motor in avehicle, the subframe assembly including: a crossmember; an arm membercoupled to each end of the crossmember; and a corner member coupled toeach arm member adjacent to a corresponding intersection with thecrossmember, wherein each corner member includes an upwardly protrudingshelf structure defining a plurality of threaded holes adapted toreceive a plurality of attachment bolts for securing a correspondingengine mount or motor mount to the subframe assembly. Optionally, eachcorner member includes a horizontal arm disposed along an upper surfaceof the corresponding arm member and a vertical arm disposed along anoutboard surface of the corresponding arm member, and wherein thehorizontal arm includes the upwardly protruding shelf structure definingthe plurality of threaded holes adapted to receive the plurality ofattachment bolts for securing the corresponding engine mount or motormount to the subframe assembly. Optionally, the crossmember defines oneor more additional threaded holes at each end adapted to receive acorresponding one or more additional attachment bolts for securing thecorresponding engine mount or motor mount to the subframe assembly.Optionally, the subframe assembly also includes an additionalcrossmember coupled between the arm members. Each of the arm members isan elongate extruded structure. Each of the corner members is also anextruded structure. When used, the horizontal arm and the vertical armof each corner member are welded to the corresponding upper surface andoutboard surface of the corresponding arm member, respectively.Alternatively, the horizontal arm and the vertical arm of each cornermember are integrally formed with the corresponding upper surface andoutboard surface of the corresponding arm member, respectively. Eachcorner member includes a horizontal planar member coupled to thecorresponding vertical arm. Optionally, the horizontal planar member iscoupled to the corresponding vertical arm by an intervening angled armmember.

In another exemplary embodiment, the present disclosure provides acorner member for a subframe assembly including a crossmember and an armmember coupled to each end of the crossmember and adapted to receive andsecure an engine or a motor in a vehicle, the corner member including:an upwardly protruding shelf structure defining a plurality of threadedholes adapted to receive a plurality of attachment bolts for securing acorresponding engine mount or motor mount to the subframe assembly.Optionally, the corner member also includes a horizontal arm adapted tobe disposed along an upper surface of a corresponding arm member and avertical arm adapted to be disposed along an outboard surface of thecorresponding arm member, wherein the horizontal arm includes theupwardly protruding shelf structure defining the plurality of threadedholes adapted to receive the plurality of attachment bolts for securingthe corresponding engine mount or motor mount to the subframe assembly.Optionally, the crossmember defines one or more additional threadedholes at each end adapted to receive a corresponding one or moreadditional attachment bolts for securing the corresponding engine mountor motor mount to the subframe assembly. Optionally, the subframefurther includes an additional crossmember coupled between the armmembers. Each of the arm members is an elongate extruded structure. Thecorner member is also an extruded structure. When used, the horizontalarm and the vertical arm are adapted to be welded to the correspondingupper surface and outboard surface of the corresponding arm member,respectively. Alternatively, the horizontal arm and the vertical arm areadapted to be integrally formed with the corresponding upper surface andoutboard surface of the corresponding arm member, respectively. Thecorner member further includes a horizontal planar member coupled to thevertical arm. Optionally, the horizontal planar member is coupled to thevertical arm by an intervening angled arm member.

In a further exemplary embodiment, the present disclosure provides avehicle, including: a propulsion device (i.e., an engine or a motor); aplurality of mounts (e.g., engine mounts or motor mounts) coupled to theengine or the motor; and a subframe assembly, including: a crossmember;an extruded arm member coupled to each end of the crossmember; and anextruded corner member coupled to each arm member adjacent to acorresponding intersection with the crossmember, wherein each cornermember includes a horizontal arm disposed along an upper surface of thecorresponding arm member and a vertical arm disposed along an outboardsurface of the corresponding arm member, wherein the horizontal armincludes an upwardly protruding shelf structure defining a plurality ofthreaded holes adapted to receive a plurality of attachment bolts forsecuring a corresponding engine mount or motor mount to the subframeassembly, and wherein each corner member includes a horizontal planarmember coupled to the corresponding vertical arm. Optionally, thecrossmember defines one or more additional threaded holes at each endadapted to receive a corresponding one or more additional attachmentbolts for securing the corresponding engine mount or motor mount to thesubframe assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is illustrated and described herein withreference to the various drawings, in which like reference numbers areused to denote like assembly components/method steps, and in which:

FIG. 1 is a partial perspective view of one exemplary embodiment of the(front) subframe assembly of the present disclosure, highlighting theassociated (left-front) extruded corner member and shelf structure;

FIG. 2 is a cross-sectional end view of one exemplary embodiment of the(left-front) extruded corner member (or corner extrusion) of the presentdisclosure, highlighting the associated shelf structure;

FIG. 3 is a partial cross-sectional end view of one exemplary embodimentof the (front) subframe assembly of the present disclosure, againhighlighting the associated (left-front) extruded corner member andshelf structure;

FIG. 4 is a partial perspective view of one exemplary embodiment of the(front) subframe assembly of the present disclosure with a (left-front)engine mount or motor mount secured to the shelf structure andcrossmember from above using bolts; and

FIG. 5 is a perspective view of one exemplary embodiment of the (front)subframe assembly of the present disclosure with four motor mounts and amotor secured to the shelf structures and crossmembers from above usingbolts.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

The present disclosure provides a subframe assembly that is adapted toreceive and secure an engine or motor (i.e., a propulsion device) in avehicle. The subframe assembly generally includes an extruded aluminumcrossmember and an extruded aluminum arm member coupled to each end ofthe crossmember. An extruded aluminum corner member is coupled to eacharm member adjacent to a corresponding intersection with thecrossmember. Each corner member includes an upwardly protruding shelfstructure itself defining a plurality of threaded holes adapted toreceive a plurality of attachment bolts for securing the correspondingmount ((e.g., engine mount or motor mount) to the subframe assembly.This shelf structure is a solid structure that is extruded with theremainder of the corner member, providing an integrated structure thatavoids the brittleness problems associated with cast components and thefailure problems associated with welded components. Each corner memberincludes a horizontal arm disposed along an upper surface of thecorresponding arm member and a vertical arm disposed along an outboardsurface of the corresponding arm member. The horizontal arm comprisesthe upwardly protruding shelf structure defining the plurality ofthreaded holes adapted to receive the plurality of attachment bolts forsecuring the corresponding engine mount or motor mount to the subframeassembly. The crossmember defines one or more additional threaded holesat each end adapted to receive a corresponding one or more additionalattachment bolts for securing the corresponding engine mount or motormount to the subframe assembly. Additional crossmembers may be utilizedand, again, each of the crossmembers, arm members, and corner membersmay be extruded structures, with the uninterrupted length of the armmembers being maximized. It should be noted that a front subframeassembly and front engine mounts or motor mounts are the general focusof the present disclosure, however the principles thereof apply equallyto rear engine mounts or motor mounts and/or a rear subframe assembly,when applicable.

This arrangement allows the mounts (i.e., engine mounts or motor mounts)to be assembled from above, providing ergonomic advantages, whileeliminating the use of longer bolts and threaded sleeves within the armmembers and corner members. The use of four threaded holes integratedinto the front corner extrusions and only two threaded sleeves in thefront crossmember provide design freedom in the size and section of theelongate extruded arms members. The sleeves and associated welds in thearm members and corner members are eliminated or reduced, as well asprotrusion of the sleeves, welds, washers, and bolt heads beneath (orabove) the arm members, which could amount to 20-30 mm in total. Qualityissues associated with thread brakes, weld distortions, and anglemismatches are also eliminated. The use of extruded arm and cornermembers provides high strength and ductility for load absorption,especially when aluminum is used, such that undesirable bending andstack-up are avoided in a crash. This prevents the subframe assemblyfrom undesirably detaching from the vehicle.

Referring now specifically to FIG. 1, in one exemplary embodiment, thesubframe assembly 10 of the present disclosure includes a crossmember12, which may be an extruded metal (e.g., aluminum) structure, and anarm member 14, which may also be an extruded metal (e.g., aluminum)structure, coupled to each end of the crossmember 12. By way of example,two crossmembers 12 and two arm members 14 may form a generallyrectangular frame structure, which may include other spanning membersthat provide the frame structure with structural integrity andstability. A corner member 16, which may further be an extruded metal(e.g., aluminum) structure, is coupled to each arm member 14 adjacent toa corresponding intersection with the crossmember 12. In the exemplaryembodiment illustrated, at least the arm members 14 are rectangularextruded structures including internal reinforcement ribs. Thecrossmember 12 is a rectangular extruded structure as well, and thecrossmember(s) 12 is/are welded or otherwise affixed to the arm members14. The use of extruded aluminum structures provides desired ductilityand strength in the event of a crash, while keeping weight to a minimum.

Each corner member 16 includes an upwardly protruding shelf structure 18that defines a plurality of threaded holes 20 adapted to receive aplurality of attachment bolts 22 (FIG. 4) for securing a correspondingengine mount or motor mount 24 (FIGS. 4 and 5) to the subframe assembly10. The shelf structure 18 is a prismatic structure (or a plurality ofadjacent prismatic structures) that is/are preferably solid.Alternatively, the prismatic structure(s) may be hollow and include(s)threaded internal sleeves that form the plurality of threaded holes 20,although this compromises the desired manufacturing simplicity somewhat.In one exemplary embodiment, the top surface of the shelf structure 18is 25-35 mm above the top surface of the associated arm member 14,providing adequate purchase for the associated bolts 22. Each shelfstructure 18 may, for example, be welded or otherwise secured directlyto the top surface of the associated arm member 14. Functionally, theshelf structures 18 provide raised points of attachment for the enginemounts or motor mounts 24 such that the associated attachment bolts 22do not have to engage sleeves or the like disposed through the armmembers 14. As is illustrated in FIG. 2, the shelf structure 18 mayinclude an inboard radius 19 at the base thereof, where the base meetsthe arm member 14 or the remainder of the corner member 16.

Referring now specifically to FIGS. 1-3, in a preferred embodiment, eachcorner member 16 includes a horizontal arm 26 disposed along an uppersurface of the corresponding arm member 14 and a vertical arm 28disposed along an outboard surface of the corresponding arm member 14.The horizontal arm 26 and the vertical arm 28 can be welded or otherwiseaffixed to the associated arm member surfaces or, as described hereinabove, the horizontal arm 26 and the vertical arm 28 can be integrallyformed with the associated arm member 14. The horizontal arm 26 includesthe upwardly protruding shelf structure 18 defining the plurality ofthreaded holes 20 adapted to receive the plurality of attachment bolts22 (FIG. 4) for securing the corresponding engine mount or motor mount24 (FIGS. 4 and 5) to the subframe assembly 10. The crossmember 12 alsodefines one or more additional threaded holes 30 at each end adapted toreceive a corresponding one or more additional attachment bolts 32 (FIG.4) for securing the corresponding engine mount or motor mount 24 to thesubframe assembly 10. Here, the threaded holes 30 of the crossmember 12are formed via traditional sleeves 34 disposed and welded in/through thecrossmember 12. As alluded to herein above, the holes 20 formed in theshelf structure 18 are preferably disposed above the surface level ofthe holes 30 formed in the crossmember 12, to match the various offsetretention arms of the various engine mounts or motor mounts 24. Again,all components described herein may be manufactured from a metal, suchas aluminum, providing the desired strength and ductility.

The subframe assembly 10 also includes an additional crossmember (notillustrated) coupled between the arm members 14, rounding out theresulting frame structure. Again, each of the arm members 14 ispreferably an elongate extruded structure. Each of the corner members ispreferably also an extruded structure. The horizontal arm 26 and thevertical arm 28 of each corner member 16 are optionally welded orotherwise affixed to the corresponding upper surface and outboardsurface of the corresponding arm member 14. In the exemplary embodimentillustrated, the horizontal arm 26 is cut-away in front of the shelfstructure 18 for weight savings purposes. Alternatively, the horizontalarm 26 and the vertical arm 28 of each corner member 16 are integrallyformed with the corresponding upper surface and outboard surface of thecorresponding arm member 14.

Each corner member 16 further includes an extruded horizontal planarmember 36 coupled to the corresponding vertical arm 28 and/or theoutboard surface of the associated arm member 14. The horizontal planarmember 36 is coupled to the corresponding vertical arm 28 and/or theoutboard surface of the associated arm member 14 by an angled arm member38. This angled arm member 38 is configured such that the top surface ofthe horizontal planar member 36 sits above the top surface of theassociated arm member 14 and shelf structure 18. It will be readilyapparent to those of ordinary skill in the art that the relativeconfiguration, position and orientation of the various components of thesubframe assembly 10 can be varied to conform to the setup of aparticular vehicle, as desired. The horizontal planar member 36 maydefine any number and arrangement of other holes, ports, and aperturesto accommodate a variety of additional coupled components and the like.In the exemplary embodiment illustrated, the back edge of eachhorizontal planar member 36 is angled for weight savings and to fitwithin vehicle space constraints.

Referring specifically to FIG. 2, in one exemplary embodiment, eachcorner member 16 includes a horizontal arm 26 that is disposedsubstantially perpendicularly to the vertical arm, to correspond to thesubstantially perpendicular top and outboard surfaces of the associatedarm member 14 (FIGS. 1, 3, and 4). This conformal arrangement allows thecorner member 16 to be securely welded or otherwise affixed to the armmember 14. A bottom arm is generally not required or used to couple thecorner member 16 to the arm member 14 as a c-shaped connection would beformed and create potential manufacturing tolerance and fit issues.However, this possibility is not excluded. The horizontal planar member36 and angled arm member 38 include associated top and bottom members 36a, 36 b, 38 a, and 38 b, respectively—forming a unitary prismaticstructure. The horizontal planar member 36 may be closed by a verticalwall 36 c and separated from the angled arm member 38 by anothervertical wall 38 c. It will be readily apparent to those of ordinaryskill in the art that any number or configuration of other internalstructures may be provided as well. During manufacturing, the horizontalarm 26 of each corner member 16 is typically first welded to the topsurface of the associated arm member 14. The vertical arm 28 of thecorner member 16 is then pressed into contact with the outboard surfaceof the arm member 14 and welded, thereby securing the corner member 16to the arm member 14 with the shelf structure 18 in the appropriateposition and orientation.

FIG. 4 is a partial perspective view of one exemplary embodiment of the(front) subframe assembly 10 of the present disclosure with a(left-front) engine mount or motor mount 24 secured to the shelfstructure 18 and crossmember 12 from above using bolts 22 and 32. Asalluded to herein above, the holes 20 (FIG. 1) formed in the shelfstructure 18 are preferably disposed above the surface level of thecorresponding hole 30 (FIG. 1) formed in the crossmember 12, to matchthe various offset retention arms of the engine mount or motor mount 24.Further, the top surface of the horizontal planar member 36 generallysits above the top surface of the associated arm member 14 and shelfstructure 18, which sits above the top surface of the crossmember 12. Inthis preferred embodiment, the shelf structure 18 is integrally formedwith the corner member 16. With the bolts 22 and 32, appropriate washersand/or vibration dampers may also be utilized.

FIG. 5 is a perspective view of one exemplary embodiment of the (front)subframe assembly 10 of the present disclosure with four motor mounts 24and a motor 40 secured to the shelf structures 18 and crossmembers 12from above using bolts (not illustrated).

Thus, referring to FIGS. 1-5, the present disclosure provides a subframeassembly 10 that is adapted to receive and secure an engine or a motor40 in a vehicle. The subframe assembly 10 generally includes an extrudedaluminum crossmember 12 and an extruded aluminum arm member 14 coupledto each end of the crossmember 12. An extruded aluminum corner member 16is coupled to each arm member 14 adjacent to a correspondingintersection with the crossmember 12. Each corner member 16 includes anupwardly protruding shelf structure 18 itself defining a plurality ofthreaded holes 20 adapted to receive a plurality of attachment bolts 22for securing the corresponding engine mount or motor mount 24 to thesubframe assembly 10. This shelf structure 18 is a solid structure thatis extruded with the remainder of the corner member 16, providing anintegrated structure that avoids the brittleness problems associatedwith cast components and the failure problems associated with weldedcomponents. Each corner member 16 includes a horizontal arm 26 disposedalong an upper surface of the corresponding arm member 14 and a verticalarm 28 disposed along an outboard surface of the corresponding armmember 14. The horizontal arm 26 comprises the upwardly protruding shelfstructure 18 defining the plurality of threaded holes 20 adapted toreceive the plurality of attachment bolts 22 for securing thecorresponding engine mount or motor mount 24 to the subframe assembly10. The crossmember 12 defines one or more additional threaded holes 32at each end adapted to receive a corresponding one or more additionalattachment bolts for securing the corresponding engine mount or motormount 24 to the subframe assembly 10. Additional crossmembers (notillustrated) may be utilized and, again, each of the crossmembers 12,arm members 14, and corner members 16 may be extruded structures, withthe uninterrupted length of the arm members 14 being maximized. Itshould be noted that a front subframe assembly 10 and front enginemounts or motor mounts 24 are the general focus of the presentdisclosure, however the principles thereof apply equally to rear enginemounts or motor mounts 24 and/or a rear subframe assembly 10, whenapplicable.

Again, this arrangement allows the engine mounts or motor mounts 24 tobe assembled from above, providing ergonomic advantages, whileeliminating the use of longer bolts and threaded sleeves within the armmembers 14 and corner members 16. The use of four threaded holes 20integrated into the front corner extrusions 16 and only two threadedsleeves 34 in the front crossmember 12 provide design freedom in thesize and section of the elongate extruded arms members 14. The sleevesand associated welds in the arm members 14 and corner members 16 areeliminated or reduced, as well as protrusion of the sleeves, welds,washers, and bolt heads beneath (or above) the arm members, which couldamount to 20-30 mm in total. Quality issues associated with threadbrakes, weld distortions, and angle mismatches are also eliminated. Theuse of extruded arm 14 and corner members 16 provides high strength andductility for load absorption, especially when aluminum is used, suchthat undesirable bending and stack-up are avoided in a crash. Thisprevents the subframe assembly 10 from undesirably detaching from thevehicle.

Although the present disclosure is illustrated and described herein withreference to preferred embodiments and specific examples thereof, itwill be readily apparent to those of ordinary skill in the art thatother embodiments and examples may perform similar functions and/orachieve like results. All such equivalent embodiments and examples arewithin the spirit and scope of the present disclosure, are contemplatedthereby, and are intended to be covered by the following non-limitingclaims for all purposes.

What is claimed is:
 1. A subframe assembly for a vehicle, comprising: acrossmember; an arm member coupled to each end of the crossmember; and acorner member coupled to each arm member adjacent to a correspondingintersection with the crossmember, wherein each corner member comprisesan upwardly protruding shelf structure defining a threaded hole adaptedto receive an attachment bolt for securing a corresponding mount to thesubframe assembly; wherein each corner member comprises a horizontal armdisposed along an upper surface of the corresponding arm member and avertical arm disposed along an outboard surface of the corresponding armmember, and wherein the horizontal arm comprises the upwardly protrudingshelf structure defining the threaded hole.
 2. The subframe assembly ofclaim 1, wherein the horizontal arm and the vertical arm of each cornermember are welded to the corresponding upper surface and outboardsurface of the corresponding arm member, respectively.
 3. The subframeassembly of claim 1, wherein the horizontal arm and the vertical arm ofeach corner member are coupled to the corresponding upper surface andoutboard surface of the corresponding arm member, respectively.
 4. Thesubframe assembly of claim 1, wherein each corner member comprises ahorizontal planar member coupled to the corresponding vertical arm. 5.The subframe assembly of claim 4, wherein the horizontal planar memberis coupled to the corresponding vertical arm by an intervening angledarm member.
 6. The subframe assembly of claim 1, wherein the crossmemberdefines a threaded hole at each end adapted to receive a correspondingsecond attachment bolt.
 7. The subframe assembly of claim 1, furthercomprising a second crossmember coupled between the arm members.
 8. Thesubframe assembly of claim 1, wherein each of the arm members is anelongate extruded structure and each of the corner members is anextruded structure.
 9. A corner member for a subframe assembly for avehicle, comprising: an upwardly protruding shelf structure defining athreaded hole adapted to receive an attachment bolt for securing acorresponding mount to the subframe assembly; and a horizontal armadapted to be disposed along an upper surface of a corresponding armmember of the subframe assembly and a vertical arm adapted to bedisposed along an outboard surface of the corresponding arm member ofthe subframe assembly, wherein the horizontal arm comprises the upwardlyprotruding shelf structure defining the threaded hole.
 10. The cornermember of claim 9, wherein the horizontal arm and the vertical arm areadapted to be welded to the corresponding upper surface and outboardsurface of the corresponding arm member, respectively.
 11. The cornermember of claim 9, wherein the horizontal arm and the vertical arm areadapted to be coupled to the corresponding upper surface and outboardsurface of the corresponding arm member, respectively.
 12. The cornermember of claim 9, further comprising a horizontal planar member coupledto the vertical arm.
 13. The corner member of claim 12, wherein thehorizontal planar member is coupled to the vertical arm by anintervening angled arm member.
 14. The corner member of claim 9, whereinthe subframe assembly to which the corner member is adapted to becoupled includes a crossmember coupled between arm members of thesubframe assembly that defines a threaded hole at each end adapted toreceive a corresponding second attachment bolt.
 15. The corner member ofclaim 14, wherein the subframe assembly to which the corner member isadapted to be coupled further includes a second crossmember coupledbetween the arm members.
 16. The corner member of claim 14, wherein eachof the arm members is an elongate extruded structure and the cornermember is an extruded structure.
 17. A vehicle, comprising: a propulsiondevice; mounts coupled to the propulsion device; and a subframeassembly, comprising: a crossmember; an extruded arm member coupled toeach end of the crossmember; and an extruded corner member coupled toeach arm member adjacent to a corresponding intersection with thecrossmember, wherein each corner member comprises a horizontal armdisposed along an upper surface of the corresponding arm member and avertical arm disposed along an outboard surface of the corresponding armmember, wherein the horizontal arm comprises an upwardly protrudingshelf structure defining a threaded hole adapted to receive anattachment bolt for securing a corresponding mount to the subframeassembly, and wherein each corner member comprises a horizontal planarmember coupled to the corresponding vertical arm.
 18. The vehicle ofclaim 17, wherein the crossmember defines a threaded hole at each endadapted to receive a corresponding second attachment bolt.